-blast. A suffix meaning an immature precursor cell of the type indicated by the preceding word. [G. blastos, germ]. immature precursor cell type; the cell type is denoted by the preceding syllables, e.g. osteoblast.
(plural defining moments) A moment in time that defines something, such as a person's success or failure, achievement or demise, talent, etc. A point at which the essential nature or character of a person, group, etc., is revealed or identified.
Learner's definition of MOMENT. 1. [count] : a very short period of time. The sunshine that was here a moment [=minute, second] ago is gone. The sun was shining. Moments later, it began to rain. It was a moment before she realized what had happened. She stopped for a moment and peeked into the window.