The term 'wearing one's birthday suit' is a colloquial expression for being nude. The crossword solutions for this term are 'nude' (4 letters) and 'nakedasajaybird' (15 letters). The first solution, 'nude, ' is a straightforward word for being without clothing. The second solution, 'nakedasajaybird, ' is a play on words, as it combines the words 'naked' and 'jaybird, ' which is another term for being nude.