IPA: /ˈpɒsəblɪst/
KK: /ˈpɑsəblɪst/
The highest degree of being able to happen or be done; the most likely to occur.
This is the possiblest solution to our problem.
This word originates from the adjective 'possible' (from Latin 'possibilis', meaning able to be done) combined with the superlative suffix '-est' (meaning most). The word 'possiblest' refers to the most able to be done or the highest degree of possibility.
Think of 'able to be done' ('possibilis') and remember that 'possiblest' means the most able to be done.