Twofold, having a double purpose or nature.
Having two separate parts, often adjoined by a line (or sometimes a space), e.g. Wright-Phillips.
Used other than figuratively or idiomatically: see double, barrelled. Having two barrels, as a gun.
Forceful, powerful (like a double-barrelled shotgun).
having an arity of two (taking two arguments or operands)
Pertaining to a dyad, the number two; of two parts or elements.
Pertaining to the physical sex of a person who is exactly male or female in genetics, anatomy and hormone levels; not intersex.
The sum of two or more dyads