federate

v [I] (of states, organizations, etc) unite into a federation （指州、 团体等）组成联邦, 结成同盟.

feather bed, feather-bed, feather-brained, featherweight, feathery, feature, featureless, Feb, febrile, February, fecal, feces, feckless, fecklessly, fecklessness, fecund, fecundity, Fed, fed up, federal, federation, fee, feeble, feeble-minded, feebleness, feebly, feed, feed in, feed on, feed up, feed with, feedback, feedbag, feeder, feeding-bottle, feel, feel about, feel amused at, feel bitter at, feel envy at,