infinity noun
1 endless space/time
VERB + INFINITY extend into/to, stretch into/to Theoretically, a line can extend into infinity.
PREP. at ~ Parallel lines meet at infinity. | into ~ In this weather the cliff face was a foggy drop into infinity.
2 number larger than any other
VERB + INFINITY approach, tend to/towards As x approaches infinity y approaches zero.
PREP. at ~ The usual convention is to choose the reference point at infinity.
You can also check other dicts: infinity (English, 中文解释 ), wordnet sense, Collins Definition