1 used with superlatives, and with all and every, to emphasize that sth is the best, worst, etc. that you can imagine, or includes every possible example:
The house has the most spectacular views imaginable. * They stock every imaginable type of pasta. * Each trainee must be able to respond effectively to all imaginable crises.
2 possible to imagine:
These technological developments were hardly imaginable 30 years ago.
