diff --git a/docs/examples/log_failed_transfers.c b/docs/examples/log_failed_transfers.c
index fb6dea6aca..3279703176 100644
--- a/docs/examples/log_failed_transfers.c
+++ b/docs/examples/log_failed_transfers.c
@@ -54,7 +54,7 @@
 #endif
 
 struct mem {
-  /* 'buf' points to memory contents that is always zero terminated so that it
+  /* 'buf' points to memory contents that is always null-terminated so that it
      can be treated like a string if appropriate. 'recent' points to the most
      recent data written to 'buf'. */
   char *buf, *recent;
diff --git a/docs/examples/synctime.c b/docs/examples/synctime.c
index 8ee5559068..02cbefa0e5 100644
--- a/docs/examples/synctime.c
+++ b/docs/examples/synctime.c
@@ -114,7 +114,7 @@ static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *stream)
   return nmemb * size;
 }
 
-/* Remember: do not assume headers are passed on null terminated! */
+/* Remember: do not assume headers are passed on null-terminated! */
 static size_t SyncTime_CURL_WriteHeader(void *ptr, size_t size, size_t nmemb,
                                         void *stream)
 {
@@ -135,7 +135,7 @@ static size_t SyncTime_CURL_WriteHeader(void *ptr, size_t size, size_t nmemb,
       *TmpStr1 = 0;
       *TmpStr2 = 0;
       if(nmemb && (field[nmemb] == '\n')) {
-        field[nmemb] = 0; /* null terminated */
+        field[nmemb] = 0; /* null-terminated */
         RetVal = sscanf(field, "Date: %25s %hu %25s %hu %hu:%hu:%hu",
                         TmpStr1, &SYSTime.wDay, TmpStr2, &SYSTime.wYear,
                         &SYSTime.wHour, &SYSTime.wMinute,
diff --git a/docs/internals/BUFREF.md b/docs/internals/BUFREF.md
index 46f7ee6b3e..09413dea03 100644
--- a/docs/internals/BUFREF.md
+++ b/docs/internals/BUFREF.md
@@ -101,4 +101,4 @@ char *Curl_bufref_dup(const struct bufref *br);
 ```
 
 Returns a strdup() version of the buffer. Note that this assumes that the
-bufref is null terminated.
+bufref is null-terminated.
diff --git a/lib/curlx/base64.c b/lib/curlx/base64.c
index a7a6703099..7f51576f50 100644
--- a/lib/curlx/base64.c
+++ b/lib/curlx/base64.c
@@ -149,7 +149,7 @@ CURLcode curlx_base64_decode(const char *src,
     pos += 3 - padding;
   }
 
-  /* Zero terminate */
+  /* Null-terminate */
   *pos = '\0';
 
   /* Return the decoded data */
@@ -213,7 +213,7 @@ static CURLcode base64_encode(const char *table64,
     }
   }
 
-  /* Zero terminate */
+  /* Null-terminate */
   *output = '\0';
 
   /* Return the pointer to the new data (allocated memory) */
diff --git a/lib/http.c b/lib/http.c
index 6083c2c4ba..aa34b5d14f 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -4187,7 +4187,7 @@ static CURLcode http_rw_hd(struct Curl_easy *data,
   CURLcode result = CURLE_OK;
   struct SingleRequest *k = &data->req;
   int writetype;
-  DEBUGASSERT(!hd[hdlen]); /* null terminated */
+  DEBUGASSERT(!hd[hdlen]); /* null-terminated */
 
   *pconsumed = 0;
   if((0x0a == *hd) || (0x0d == *hd)) {
@@ -4548,7 +4548,7 @@ CURLcode Curl_http_write_resp_hd(struct Curl_easy *data,
   CURLcode result;
   size_t consumed;
   char tmp = 0;
-  DEBUGASSERT(!hd[hdlen]); /* null terminated */
+  DEBUGASSERT(!hd[hdlen]); /* null-terminated */
 
   result = http_rw_hd(data, hd, hdlen, &tmp, 0, &consumed);
   if(!result && is_eos) {
diff --git a/lib/transfer.c b/lib/transfer.c
index 63c8fcd4db..5c96aed7d6 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -794,7 +794,7 @@ CURLcode Curl_xfer_write_resp_hd(struct Curl_easy *data,
                                  const char *hd0, size_t hdlen, bool is_eos)
 {
   if(data->conn->scheme->run->write_resp_hd) {
-    DEBUGASSERT(!hd0[hdlen]); /* null terminated */
+    DEBUGASSERT(!hd0[hdlen]); /* null-terminated */
     /* protocol handlers offering this function take full responsibility
      * for writing all received download data to the client. */
     return data->conn->scheme->run->write_resp_hd(data, hd0, hdlen, is_eos);
diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c
index b12e23481b..7909467dea 100644
--- a/lib/vtls/mbedtls.c
+++ b/lib/vtls/mbedtls.c
@@ -517,7 +517,7 @@ static CURLcode mbed_load_cacert(struct Curl_cfilter *cf,
       curlx_free(newblob);
     }
 #else
-    /* DER encoded certs do not need to be null terminated because it is a
+    /* DER encoded certs do not need to be null-terminated because it is a
        binary format. Thus, if we are not compiling with PEM_PARSE we can avoid
        the extra memory copies altogether. */
     ret = mbedtls_x509_crt_parse_der(&backend->cacert, ca_info_blob->data,
@@ -630,7 +630,7 @@ static CURLcode mbed_load_clicert(struct Curl_cfilter *cf,
       curlx_free(newblob);
     }
 #else
-    /* DER encoded certs do not need to be null terminated because it is a
+    /* DER encoded certs do not need to be null-terminated because it is a
        binary format. Thus, if we are not compiling with PEM_PARSE we can avoid
        the extra memory copies altogether. */
     ret = mbedtls_x509_crt_parse_der(&backend->clicert, ssl_cert_blob->data,
diff --git a/scripts/badwords.txt b/scripts/badwords.txt
index 7a57016dca..414d67a7d2 100644
--- a/scripts/badwords.txt
+++ b/scripts/badwords.txt
@@ -19,6 +19,8 @@ wild card:wildcard
 thread safe:thread-safe
 thread unsafe:thread-unsafe
 multi thread:multi-thread
+null terminated:null-terminated
+zero terminated:null-terminated
 it's:it is
 aren't:are not
 can't:cannot