1the hindmost part of an animal, especially when prolonged beyond the rest of the body, such as the flexible extension of the backbone in a vertebrate, the feathers at the hind end of a bird, or a terminal appendage in an insect:the dog’s tail began to wag frantically
a slender backward prolongation of each hindwing in some butterflies.
2a thing resembling an animal’s tail in its shape or position, typically extending downwards or outwards at the end of something:the tail of a capital Q
the rear part of an aeroplane, with the tailplane and rudder:the fuselage tapers sharply towards the tail
the lower or hanging part of a garment, especially the back of a shirt or coat:he wiped his hands on the tail of his grubby vesthe stormed off, the tails of his jacket flapping behind him
(tails) informal a tailcoat, or a man’s formal evening suit with a tailcoat:the men looked debonair in white tie and tails
the luminous trail of particles following a comet.
the lower end of a pool or stream:shallow riffles and the tails of pools are prime feeding areas
the exposed end of a slate or tile in a roof:the slates are dressed with the bevelled tail and edge characteristic of thick, square stone roofing
Mathematics an extremity of a curve approaching the horizontal axis of a graph, especially that of a frequency distribution.
3the end of a long train or line of people or vehicles:a catering truck at the tail of the convoy
the final, more distant, or weaker part of something:the tail of a hurricane
Cricket the end of the batting order, with the weakest batsmen:McDermott worked his way through the tail, finishing with ten wickets
4 informal a person secretly following another to observe their movements:I can’t put a tail on him, I don’t know where he’s gone
5 informal, chiefly North American a person’s buttocks:the coach kicked Ryan in his tail
vulgar slang a woman’s genitals.
[mass noun] informal women collectively regarded in sexual terms:my wife thinks going out with you guys will keep me from chasing tail
6 (tails) the side of a coin without the image of a head on it (used when tossing a coin to determine a winner):the chances of heads and tails in the long run are equal
1 informal follow and observe (someone) closely, especially in secret:a flock of paparazzi had tailed them all over London
[no object, with adverbial of direction] follow:they went to their favourite cafe—Owen and Sally tailed along
2 [no object, with adverbial of direction]North American (of an object in flight) drift or curve in a particular direction:the next pitch tailed in on me at the last second
3remove the stalks or ends of (fruit or vegetables) in preparation for cooking.
4pull on the end of (a rope) after it has been wrapped round the drum of a winch a few times, in order to prevent slipping when the winch rotates.
5 archaic join (one thing) to another.
chase one's (own) tail
informal rush around ineffectually:from continually chasing my tail and being late for everything, punctuality became second nature
on someone's tail
following someone closely:a police car stayed on his tail for half a mile
the tail of one's eye
dated the outer corner of one’s eye:he glanced at her through the tail of his eye
the tail wags the dog
the less important or subsidiary factor, person, or thing dominates a situation; the usual roles are reversed:the financing system is becoming the tail that wags the dog
with one's tail between one's legs
informal in a state of dejection or humiliation:we took Lily in when she came back from London with her tail between her legs
with one's tail up
informal in a confident or cheerful mood:the West Indies team with their tails up can be awesome
British (of traffic) become congested and form a tailback:traffic tailed back fourteen miles after a chemical spillage
tail something in (or into)
insert the end of a beam, stone, or brick into (a wall).
tail off (or away)
gradually diminish in amount, strength, or intensity:the economic boom was beginning to tail off