adjective - extremely difficult to solve

adjective - feeling embarrassed and ashamed

adjective - tests, rules or processes that are strict

adjective - done very carefully and with great attention to detail

noun - a sudden and unaccountable change in attitude or behaviour

noun - a type of exercise in which you do a squat, kick your feet back into a plank position and then back and then you stand up straight again

noun - a kind of exercise in which you lie flat and then raise your legs and body towards each other, touching your toes with your fingers

noun - a kind of exercise in which you lie flat and then raise your legs and body towards each other, touching your toes with your fingers

noun, formal - the quality of not being affected by time

adverb - in a way that is not affected by time

noun - an event where things are sold to the people who offer the highest price

noun - a particular moment something happens, the act of doing something at a particular moment

verb - to do something at the wrong moment

adjective - connected with the group of politicians who do not want social change and emphasize business and market

adjective - not having the kind of effect you hope for