Looking up...
She mostly works from home.
She works from home more often than not.
for the greatest part; mainly
He mostly eats vegetables.
Vegetables make up the majority of his diet.
The movie was mostly boring.
Most of the movie was uninteresting.
Often used to indicate that something is true in most cases, though not always.
Use 'mostly' to describe something that is true in most cases but not always.
Use 'mostly' to emphasize the majority, but avoid it when 'usually' or 'generally' would be clearer.
From Middle English 'mostli', from 'most' + '-ly' (adverbial suffix).
Can be used to soften a statement, indicating that something is generally true but not absolute.