weigh up
Synonym discussion
Sense: phrasal verb/idiom/1
'Weigh up', 'consider', 'evaluate', and 'assess' all involve careful thought, but they differ in focus. 'Weigh up' is the most specific — it suggests literally comparing two sides, like putting items on a scale. 'Consider' is the broadest and most general; you can consider anything from a simple idea to a complex proposal. 'Evaluate' is more formal and implies assigning a value or grade to something ('evaluate a student's performance'). 'Assess' is also formal but often focuses on measuring quality, risk, or importance ('assess the damage'). In everyday conversation, 'weigh up' and 'consider' are the most natural choices; 'evaluate' and 'assess' belong in writing or professional speech. For example: 'I weighed up whether to take the train or drive' (balanced pros and cons), but 'I considered taking the train' (just a possibility) and 'The mechanic assessed the damage' (measured the extent).
Etymology
'Weigh up' comes from the literal meaning of placing something on a scale to find its weight. 'Weigh' traces back to Old English 'wegan' (to carry, move, or weigh), from Proto-Germanic '*weganą'. The sense of 'mentally balancing options' dates back to at least the 14th century. The particle 'up' was added to form the phrasal verb in the 16th century, originally meaning 'to lift' or 'to raise', and later developed the figurative sense of 'bringing considerations to the surface for examination'.