Swimming competition (4)
(Other definitions for gala that I've seen before include "Festive occasion - variety of apple" , "Jamboree" , "Festive celebration" , "Carnival, fete" , "sporting event" .)
'swimming competition' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for meet that I've seen before include "Bump into" , "Fitting to come together" , "Touch; suitable (arch.)" , "Right and fitting" , "acceptable" .)