Astronauts group left in a kind of cavity? (5)
I believe the answer is:
nasal
'kind of cavity?' is the definition.
(I've seen this in another clue)
'astronauts group left' is the wordplay.
'astronauts' becomes 'NASA' (National Aeronautics and Space Administration).
'group left' becomes 'l' (common abbreviation. I am not sure about the 'group' bit.).
'nasa'+'l'='NASAL'
'in a' is the link.
Can you help me to learn more?
(Other definitions for nasal that I've seen before include "Letter such as M or N" , "Relating to a facial organ" , "Of noses" , "Beak's" , "Like some spray" .)