Definition: Okay, here's a definition for you in two sentences, incorporating the key elements you provided:
“Profanity’s influence on perceived authenticity and helpfulness within online reviews is significantly moderated by review subjectivity – specifically, the tendency to interpret profanity as a signal of usefulness.
This suggests that while offensive, the presence of profanity can subtly shape users' judgments of a review's value and reliability, ultimately influencing their perception of its helpfulness.”