ambulatory (adj.)youdaoicibaDictYouDict[ambulatory 词源字典]
"pertaining to walking;" also "shifting, not permanent," 1620s, from Latin ambulatorius "of or pertaining to a walker; movable," from ambulator, agent noun from past participle stem of ambulare "to walk" (see amble). Middle English had ambulary "movable" (mid-15c.).[ambulatory etymology, ambulatory origin, 英语词源]
ambulatory (n.)youdaoicibaDictYouDict
from Medieval Latin ambulatorium, from Latin ambulatorius "movable," from ambulare (see amble).
perambulator (n.)youdaoicibaDictYouDict
1610s, "one who perambulates," agent noun in Latin form from perambulate. Sense of "baby carriage" is first recorded 1856; often colloquially shortened to pram.