Technically, this pet peeve is not connected to any פרשה in particular but for obvious reasons, it becomes more prevalent for פרשת בהעלותך. It's very simple -
ענִווּת - the word simply does not exist, at least not in any authoritative source that I know of. The real word for humility found everywhere that counts, for example, the very end of משניות סוטה, is ענווה. Yet you will hear people everywhere use this word, even people who are normally careful to use proper דקדוק. Unfortunately,
Google Translate does not agree with me. But that's probably because it has managed to slip into the language. How? My guess is that might be a sort of Yiddishism. Just like we have טליתים, שבתים and תעניתים when the real words are טליתות, שבתות and תעניות, many descriptive words tend to end with ות such as חסידות and התנגדות so it is assumed that the word for humility should as well. But... it doesn't.
If this word does exist somewhere and I simply haven't seen it, please correct me.
... and so MG has done in the comments. He cites two examples where the word is used by מהרש"א:
:מועד קטן ט"ז
.סוטה מ
So this is still a curious matter. Let's say the word is not used through the ראשונים and suddenly appears. Where did it come from? Indeed, לשון הקדש is an evolving language as seen throughout תנ"ך and history. We find new words arise that haven't been used before. But what makes this more puzzling is that there already exists a perfectly sufficient word in the language. Why create a new one?