assumption
noun
uk/əˈsʌmʃən/ us [ S ]
something that you accept as true, although you have no proof:
make an assumption about sb/sth We tend to make assumptions about our staff's ability based on very little evidence.
on the assumption that They decided to go ahead on the assumption that the figures they had been given were accurate.
These calculations are based on the assumption that sales will continue to rise.
[ U ]
the act of taking control of something:
the assumption of power by the army
The offer includes $1 billion in cash and the assumption of $3.5 billion in debt for TWA's aircraft leases.