TREACHEROUS

SPACETRAVELSci-fi staple OSTENTATIONVulgar display GRAVEACCENTMark on apres PETPASSPORTDocument used for a travel companion who might sit under a seat ISAACNEWTONConservative cracking nuts was Etonian genius GAMEWARDENSConservation officers MIDDLESEATSThey might be the last to be booked on an airplane FUNCTIONING? GRANDEDAMESDignified doyennes WORKINGGIRLSee note DOUBLEDUTCHGreek bigamist's requirement? HAIRTRIGGERDevice on a firearm that responds to the slightest stimulus GROUPSELFIEIt's a lot for one person to take LINEOFSIGHTSpooner’s indicator of illumination shows how much one’s able to see (4,2,5)