overlap width; pasting margin
Literal sense: the extra width left on paper or cloth for gluing pieces together. Common in crafts, bookbinding, and packaging.
封筒を作るときは、糊代を1センチほど取ってください。
When making an envelope, leave a pasting margin of about 1 cm.
Figurative extension: room to maneuver, flexibility, or a buffer in plans, schedules, or budgets. Often used in business and everyday conversation.
If you build some leeway into the schedule, you can handle sudden changes.
予算には少し糊代が必要だ。
We need a little allowance in the budget.
Standard kanji spelling; 糊 means 'paste' and 代 means 'margin' or 'allowance'.
Kana spelling is common in everyday writing, especially for the figurative sense.
Compound of 糊 (のり, 'paste') and 代 (しろ, 'margin' or 'allowance'). Originally referred to the overlapping part of paper or cloth for gluing, later extended metaphorically to any kind of buffer or leeway.