polyanthus: florists' primroses; considered a complex hybrid derived from oxlip, cowslip, and common primrose
entity: that which is perceived or known or inferred to have its own distinct existence (living or nonliving)
significant digit: any digit of a number that is known with certainty; any digit of a number beginning with the leftmost non-zero digit and ending with the rightmost non-zero digit (or a zero considered to be the exact value)