Sentence:  His bill , allegedly aimed at Hoffa , would amend the Sherman , Clayton and Norris-LaGuardia acts to authorize the issuance of federal injunctions in any transportation strike and would make it illegal for any union to <WSD>act</WSD> in concert with any other union - even a sister local in the same international . 
Meaning of the word marked with <WSD> tags:  perform an action, or work out or perform (an action)