Singular problem with zero gravity toilets (7)
I believe the answer is:
urinals
'zero gravity toilets' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Maybe they are linked in a way I don't understand?
'singular problem' is the wordplay.
I cannot quite see how this works, but
'singular' could be 's' (abbreviation in grammar) and 's' is found within the answer.
The remaining letters 'urinal' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'with' acts as a link.
Can you help me to learn more?
(Other definitions for urinals that I've seen before include "They're taking the piss" , "Plumbing fixtures in the gents" , "Plumbing fixtures for men only" .)