out-and-out

UK: /ˌaʊtəndˈaʊt/ US: (out′n out′, -nd out′)

WordReference Random House Learner's Dictionary of American English © 2025

ˈout-and-ˈout,  adj. [before a noun]

1. complete;
   absolute:
   He told an out-and-out lie.

WordReference Random House Unabridged Dictionary of American English © 2025

out-and-out  (out′n out′, -nd out′), adj. 

1. complete;
   total;
   thoroughgoing:
   an out-and-out lie.

• Middle English 1275–1325

Collins Concise English Dictionary © HarperCollins Publishers::

out-and-out adjective

1. (prenominal) thoroughgoing; complete