adjective
Having an acrid taste (usually from a basic substance).
Harsh, piercing, acerbic or stinging.
Hateful or hostile.
Cynical and resentful.
adverb
To an intense or severe degree; bitterly.
noun
(usually in the plural bitters) A liquid or powder, made from bitter herbs, used in mixed drinks or as a tonic.
A type of beer heavily flavored with hops.
(nautical) A turn of a cable about the bitts.
verb
(archaic) To make bitter.
noun
(computing, informal, in combination) A hardware system whose architecture is based around units of the specified number of bits (binary digits).