1 to form a picture in your mind of what sth might be like:
[VN] The house was just as she had imagined it. * I can't imagine life without the children now. * [V(that)] Close your eyes and imagine (that) you are in a forest. * [Vwh-] Can you imagine what it must be like to lose your job after 20 years? * [V-ing] She imagined walking into the office and handing in her resignation. * [VN-ing] I can just imagine him saying that! * [VNtoinf] I had imagined her to be older than that. * [V] (spoken) 'He was furious.' 'I can imagine.' [also VN-ADJ, VN-N]
2 to believe sth that is not true:
[V(that)] He's always imagining (that) we're talking about him behind his back. * [VN] There's nobody there. You're imagining things.
3 to think that sth is probably true
SYNSUPPOSE, ASSUME:
[V(that)] I don't imagine (that) they'll refuse. * [V] 'Can we still buy tickets for the concert?' 'I imagine so.' [also VNthat]
