To assume the appearance of, without having the reality; feign; counterfeit; pretend.
To act the part of; imitate; be like; resemble.
Specifically— In phonology, to imitate in form. See simulation, 2.
In biology, to imitate or mimic; resemble by way of protective mimicry: as, some insects simulate flowers or leaves. See mimicry, 3.
Feigned; pretended.