moderate

[1]	chair , lead
[2]	control , hold in , hold , contain , check , curb
[3]	mince , abate , calm , soften , mollify , soothe , ease , relax , alleviate , mitigate , soften , dull , blunt , cushion , relieve , reduce , lessen , remit , slacken , diminish , decrease , defuse , temper , (Colloq) let up (on)
[4]	mediate , tone down , tame , arbitrate , referee , judge , chair , supervise , preside (over) , coordinate , run , regulate , manage , direct
[5]	chasten , temper

[1]	centrist , middle of the roader , moderationist
[2]	middle-of-the-roader , non-radical , non-reactionary , centrist

adj.

[1]	temperate , calm , reasonable , cool , judicious , rational , balanced , unexcessive , modest , sober , sensible , commonsensical , controlled , deliberate , steady
[2]	centre , middle-of-the-road , non-radical , non-reactionary
[3]	fair , middling , average , ordinary , medium , middle , modest , mediocre , unexceptional , (Colloq) fair to middling
[4]	temperate
[5]	restrained