what is a spore?

Ans 1: 
spore
noun

The definition of a spore is a small organism or a single cell being that is able to grow into a new organism with the right conditions.
An example of a spore is a flower seed.

Ans 2:

spore

1. BIOL. any of various small reproductive bodies, usually consisting of a single cell, produced by bacteria, algae, mosses, ferns, certain protozoans, etc., either asexually (asexual spore) or by the union of gametes (sexual spore): they are capable of giving rise to a new adult individual, either immediately or after an interval of dormancy
2. any small organism or cell that can develop into a new individual; seed, germ, etc.

Origin of spore

Modern Latin spora ; from Gr, a sowing, seed, akin to speirein, to sow ; from Indo-European base an unverified form (s)p(h)er-, to strew, sow from source spread, sprout

spored, spor′ing

to bear or develop spores

Ans 3:

spore

noun

1. A small, usually single-celled reproductive body that is resistant to adverse environmental conditions and is capable of growing into a new organism, produced especially by certain fungi, algae, protozoans, and nonseedbearing plants such as mosses and ferns.
2. A megaspore or microspore.
3. A dormant nonreproductive body formed by certain bacteria often in response to a lack of nutrients, and characteristically being highly resistant to heat, desiccation, and destruction by chemicals or enzymes.