handrail
Synonym discussion
Sense: noun/1
All four words describe a structure that provides support or prevents falls, but each has a different focus. 'Handrail' refers specifically to the narrow bar that you hold with your hand — the part you grasp. 'Banister' is more specific: it means the handrail plus the vertical posts supporting it on the open side of a staircase. 'Rail' is the broadest term and can describe any long horizontal bar (a towel rail, a safety rail, a curtain rail). 'Railing' typically means the entire barrier system — the top rail plus the vertical balusters below it. 'Guardrail' is a safety barrier by the edge of a road, balcony, or platform. For everyday household use: if you are talking about holding it while walking up stairs, 'handrail' is the most natural word; if you are describing the whole decorative structure along the stairs, use 'banister'.
Common collocations
Etymology
A compound word formed from 'hand' (from Old English 'hand', meaning the end of the arm used for grasping) and 'rail' (from Old French 'reille', meaning a bar or rod). First recorded in English around the 1700s, describing a rail designed for the hand to grip while walking on stairs or along a passage.