Definition of "optimistic"

optimistic

/ˌɒptɪˈmɪstɪk/

adjective
comparative more optimistic, superlative most optimistic
1. Expecting the best in all possible ways.
  Quotations
  Reference was made in the January-February issue to some of the optimistic railway titles of the past, such as the Manchester & Milford, and the Lancashire, Derbyshire & East Coast, neither of which got anywhere near the extremities indicated in their titles during their independent existence.
  1944 November and December, “What's in a Name?”, in Railway Magazine, page 333
2. (computing) Allowing other processes to perform transactions on the same data at the same time, and checking for conflicts only when changes need to be written back.