IMAG'INE, verb transitive [Latin imaginor, from imago, image.]

1. To form a notion or idea in the mind; to fancy. We can imagine the figure of a horse's head united to a human body.

In this sense, fancy is the more proper word.

2. To form ideas or representations in the mind, by modifying and combining our conceptions.

3. To contrive in purpose; to scheme; to devise.

How long will ye imagine mischief against a man? Psalms 62:3.

IMAG'INE, verb intransitive To conceive; to have a notion or idea. I cannot imagine how this should have happened.