Senses
忘形 to lose one's bearings
to lose control or become unmindful of one's status or appearance due to extreme excitement or pride; often used in the phrase 得意忘形
忘形 to be informal
(literary) to disregard social status or etiquette; to be casual and unconstrained in a friendship
忘形 to forget the self
(literary) to forget one's physical body or worldly form as a state of spiritual transcendence