The term 'bottomless' is used to describe something that is seemingly endless or without limit. This can be seen in the crossword solutions given, such as 'BASELESS' (8 letters), which means having no foundation or evidence; 'UNWARRANTED' (11 letters), which means not justified or authorized; 'UNFOUNDED' (9 letters), which means having no basis in fact; 'SUBTERRANEAN' (12 letters), which means existing or occurring beneath the surface of the earth; 'CAVERNOUS' (9 letters), which means resembling a cave; 'YAWNING' (7 letters), which means extremely wide; 'unmeasured' (10 letters), which means not able to be measured; 'GRATUITOUS' (10 letters), which means given freely without charge; 'FATHOMLESS' (10 letters), which means impossible to measure or comprehend; 'GROUNDLESS' (10 letters), which means having no basis in fact; 'UNFATHOMABLE' (12 letters), which means impossible to understand; 'LIMITLESS' (9 letters), which means having no boundaries; 'PROFOUND' (8 letters), which means DEEP and meaningful; 'ABYSMAL' (7 letters), which means extremely bad; and 'DEEP' (4 letters), which means extending far down from the top or surface. All of these words are used to describe something that is seemingly endless or without limit, which is the definition of the term 'bottomless'.