These words all mean to come or bring together into an organized body or group. In their transitive uses, gather emphasizes the act of bringing widely scattered things to one place, and collect suggests discriminating selection: to collect stamps; to gather wildflowers. When used of people or animals, gather , and less frequently collect , suggest some degree of necessity or compulsion: to gather refugees into one place. In intransitive uses gather and collect are often used interchangeably.

• Autograph seekers gathered (or collected ) round the film star wherever she went; after the stirring sermon, parishioners collected (or gathered ) round the minister to congratulate him.

But gather suggests a group formed by a more random process than collect . Collect usually emphasizes a gradual process of accumulation, often one by one, whereas gather may be used to describe the spontaneous forming of a group.

• A few homeless beggars collected round the blaze for warmth; A crowd immediately gathered round the man stricken on the footpath.

Assemble refers to people or organizations and suggests their coming together for some joint purpose, though not necessarily a pre-arranged one: to assemble the staff for a special announcement by the manager; picnickers who assembled at the ferry wharf to board a chartered launch. Congregate suggests a more spontaneous or haphazard coming together. People congregated on balconies to catch a glimpse of the passing celebrity; Students congregated under the vice-chancellor’s window to protest against his decision on their representation on university bodies.

To convene is to come together or meet in a body. It is a formal word and applies particularly to the assembling of a formally organized body of people: A scientific congress convened to discuss the effects of nuclear testing on human health.

Mass means to assemble in great numbers: troops massed for an attack; Britons massing in the streets on Coronation Day. Muster is generally restricted to military use, and is applied to parts or units of a force that come or are brought together.

• Recruits muster for a roll call; a fighting force that mustered for a final attack.

Muster , like gather , collect and assemble can be used of qualities or data as well as of things.

• He could barely muster the strength to raise his head from the pillow; to muster facts; to gather impressions on a trip to Europe; to collect anecdotes in preparation for a speech; to assemble data for a legal presentation.