An automatic transmission with separate clutches for odd and even gears.

plural of Irish twin

(carpentry) A two-edged tool used in gate-type hurdle-making for cutting out mortises, with a flat chisel and a mortise chisel or hook, similar to the much larger French carpenter's tool, the besaiguë (or bisaiguë).

(relativity) The clock paradox.

plural of twibill

(idiomatic) Immediately; instantaneously. / 2007 April 28, Hugh Muir, The Guardian:

Third-person singular simple present indicative form of twiddle

simple past tense and past participle of twiddle

(mathematics) Either of a pair of prime numbers that differ by two.

The period in which the sun is less than 6° below the horizon in the morning and evening.