hance 副词，从此以后

hence [hens]
adverb
1.as an inference from this fact; for this reason; therefore: The eggs were very fresh and hence satisfactory.
2.from this time; from now: They will leave a month hence.
3.from this source or origin.4.Archaic.a.from this place; from here; away: The inn is but a quarter mile hence.b.from this world or from the living: After a long, hard life they were taken hence.c.henceforth; from this time on.
Source: dictionary.com