Ah, the joys of Anglo-Saxon exceptionalism - in other parts of the world feminists campaign for feminine titles to avoid being obscured by the masculine ones. In France there was a drawn out debate was whether female doctors should be la docteure or la doctoresse earlier it was common to use la docteur. Being a grumpy, older, ex-dark blue, white male I should probably exclude myself from this debate.
However: not wanting to disappoint BEagle and very much in jest...
Army - Solidier derives ultimately from the latin solidus (aka shilling) referring to their pay
Navy - Sailor derives from sailer i.e. someone or thing that sails
So,
Airforce - my ideas are Geographer - someone who uses maps to their own service's advantage, Boaster - someone who celebrates their own achievements, PPensioner - someone who uses PPrune to discuss pension schemes and PVR... other suggestions welcome.