1. to suppose to be the case, without proof
2. to take on or adopt (a responsibility, role, or attitude)
3. to take or begin to have (power or control)

Examples

• I assume you’re coming to the party tonight.
• Don’t assume that everyone agrees with you.
• She will assume the role of team captain next season.
• The new CEO assumed control of the company last month.
• He assumed a confident posture during the presentation.
• We can’t assume the weather will be good tomorrow.
• The government assumed emergency powers during the crisis.