Synonyms for Convenience:

n.

receptiveness, comforts, expediency, openness, unfitness, trouble, nearness, suitableness, accessibility, adaptability, usefulness, creature comforts. aid, service, luxury, benefit, handiness, help, advantage, awkwardness, assistance, appurtenance, satisfaction, comfort, discomfort, avail, amenity, relief, support, accessory, accommodation, means, succor. freedom, preference, liberty. any time, when opportune, appropriately, when one has time. amenity (noun)
facility.
application (noun)
usefulness.
approachability (noun)
accessibility.
availability, usefulness; useful thing (noun)
aid, appliance, advantage, accessory, appropriateness, service, luxury, amenity, relief, handiness, openness, support, suitability, facility, satisfaction, benefit, utility, suitableness, succor, receptiveness, fitness, accessibility, comfort, avail, accommodation, assistance, ease, help, comforts, means.
convenience (noun)
widget, gadget, gizmo, restroom, appliance, wash room, public convenience, gismo, public lavatory, contrivance, toilet facility, contraption, comfort station, public toilet.
expedience (noun)
opportunity, desirability, efficiency, fitness, timeliness, suitability, expedience, propriety, advantageousness, aptness, well-timedness, effectiveness.
fitness (noun)
auspiciousness, seasonableness.
freedom (noun)
liberty.
instrument (noun)
device, facility, contrivance, machine, engine, implement, gadget, instrument, gizmo, apparatus, equipment, contraption, tool, utensil, gimmick, appliance, utility, widget, doodad, gimcrack.
leisure (noun)
rest, ease, leisure, repose, relaxation, inactivity.
opportunity (noun)
auspiciousness, seasonableness, appropriateness, propitiousness.
serviceableness (noun)
utility.
spare time (noun)
leisure, liberty, freedom, preference, opportunity.
utility (noun)
usefulness.

v.

benefit (verb)
advantage.

Other synonyms:

amenity, creature comforts, comfort. approachability
accessibility.
convenience
accommodation.
Other relevant words:
accessibility, public toilet, expediency, appropriately, comfort, service, comfort station, receptiveness, restroom, avail, discomfort, accessory, comforts, wash room, support, nearness, assistance, public convenience, openness, succor, aid, suitableness, public lavatory, usefulness, toilet facility, preference, unfitness, means, luxury, satisfaction, gismo, awkwardness, appurtenance, relief, freedom, adaptability, liberty, advantage, amenity, benefit, handiness, trouble, accommodation, help.