(n.) The act or process of naturalizing, esp. of investing an alien with the rights and privileges of a native or citizen; also, the state of being naturalized.

Americanization about-face acclimation acclimatization accommodation acculturation accustoming adaption adjustment admission adoption affiliation alchemy assimilation assumption becoming breaking breaking-in case hardening change change-over citizenship by naturalization citizenship papers conditioning conversion culture shock domestication familiarization flip-flop growth habituation hardening housebreaking inurement lapse nationalization naturalized citizenship orientation papers passage progress re-formation reconversion reduction resolution reversal seasoning shift switch switch-over taming training transformation transit transition turning into volte-face