L (face of Losing) in GAS (at stretch could be trip but its not a good clue IMO). GALS is the defenition (lasses).
Am not sure how GELS would work ,for example theres no defenition and there seems no wordplay.
gel
[ɡɛl]
NOUN
BRITISH
informal
gel (noun) · gels (plural noun)
an upper-class or well-bred girl or young woman.
"fastidiously reared Home Counties gels"