1.Definition: (of e.g. volcanos) capable of erupting
2.Definition: (of e.g. volcanos) erupting or liable to erupt
3.Definition: (of the sun) characterized by an increased occurrence of sunspots and flares and radio emissions
4.Definition: (used of verbs (e.g. `to run') and participial adjectives (e.g. `running' in `running water')) expressing action rather than a state of being
5.Definition: characterized by energetic activity
"An active toddler", "Active as a gazelle", "An active man is a man of action"
6.Definition: disposed to take action or effectuate change
"A director who takes an active interest in corporate operations", "An active antagonism", "He was active in drawing attention to their grievances"
7.Definition: engaged in full-time work
"Active duty", "Though past retirement age he is still active in his profession"
8.Definition: engaged in or ready for military or naval operations
"On active duty"
9.Definition: exerting influence or producing a change or effect
"An active ingredient"
10.Definition: expressing that the subject of the sentence has the semantic function of actor:
"Hemingway favors active constructions"
11.Definition: full of activity or engaged in continuous activity
"An active seaport", "An active bond market", "An active account"
12.Definition: in operation
"An active tradition"
13.Definition: taking part in an activity
"An active member of the club", "He was politically active"
14.Definition: tending to become more severe or wider in scope