WordNet sense 1 (a healthy capacity for vigorous activity):

vim, vitality

WordNet sense 2 (the federal department responsible for maintaining a national energy policy of the United States; created in 1977):

doe, Department of Energy, Energy Department

WordNet sense 3 (forceful exertion):

vigor, zip, vigour

WordNet sense 4 (enterprising or ambitious drive):

get-up-and-go, push

WordNet sense 5 (an imaginative lively style (especially style of writing)):

muscularity