1.
mostly, generally, for the most part, almost
Indicates that something is largely or nearly complete, or that a statement applies in most cases.
2.
probably, most likely
Used to express a guess or supposition about something, suggesting the speaker is fairly confident.
大方 functions as both an adverb and a noun modifier.
SENSE 1 — MOSTLY:
When modifying verbs, it means "for the most part" or "nearly." When modifying nouns as 大方の + noun, it means "most" or "the majority of."
SENSE 2 — PROBABLY:
Used to make educated guesses, often paired with だろう or でしょう.