assumpsit
noun
as·sump·sit ə-ˈsəm(p)-sət 
1
: an express or implied promise or contract not under seal on which an action may be brought
2
a
: a former common-law action brought to recover damages alleged from the breach of an assumpsit
b
: an action to recover damages for breach of a contract
Word History
Etymology
New Latin, he undertook, from Latin assumere to undertake
First Known Use
1590, in the meaning defined at sense 1
Legal Definition
assumpsit
noun
as·sump·sit ə-ˈsəmp-sit
: an express or implied promise or contract or quasi contract the breach of which may be grounds for a suit
also : a common-law action that may be brought for such a breach compare covenant, debt
Note: The action of assumpsit developed in early English law and is still available in the U.S. in some jurisdictions.