(UK, idiomatic, vulgar, colloquial) To flatter or perform favors excessively, especially to receive preferential treatment from a boss or other superior; to behave obsequiously.

(genetics) Relating to heterotachy

(carpentry, of timber) Working smoothly or without splitting. / (of butter) Rancid.

(mathematics) Capable of being assigned a bijection to the natural numbers. Applied to sets which are not finite, but have a one-to-one mapping to the natural numbers.