Through  (also thro', us thru) —prep. 1 a from end to end or side to side of. B going in one side or end and out the other of. 2 between or among (swam through the waves). 3 from beginning to end of (read through the letter; went through many difficulties). 4 because of; by the agency, means, or fault of (lost it through carelessness). 5 us up to and including (monday through friday). —adv. 1 through a thing; from side to side, end to end, or beginning to end. 2 so as to be connected by telephone (will put you through). —attrib. Adj. 1 (of a journey, route, etc.) Done without a change of line or vehicle etc. Or with one ticket. 2 (of traffic) going through a place to its destination. 3 (of a road) open at both ends.  be through colloq. 1 (often foll. By with) have finished. 2 (often foll. By with) cease to have dealings. 3 have no further prospects. Through and through thoroughly, completely. [old english]