by and large

[Earlier, to (the wind) and off it, in one direction and another (said of the manner of handling a sailing vessel) : BY¹, toward + LARGE, with the wind abaft the beam.]

For the most part, generally speaking, as in By and large the novel was a success. This expression originated in 17th-century seamanship, where it referred to sailing into the wind and then off it, which made it easier to steer. By the early 1700s the term had been broadened to mean "in one direction and another," whence its present meaning of "in general." For a synonym, see for the most part.

The adverb has one meaning:

Meaning #1: usually; as a rule
  Synonyms: generally, more often than not, mostly