尽早 is an adverb meaning 'as early as possible' or 'at the earliest opportunity.' It combines 尽 (jǐn), which here means 'to the utmost extent' or 'as much as possible,' and 早 (zǎo), meaning 'early.' Together, they form a compact expression emphasizing urgency and timeliness — not just 'early,' but the earliest feasible moment. It conveys intentionality and proactive effort to act without delay.

This phrase is commonly used in formal and semi-formal contexts: work instructions, health advice, official notices, and polite requests. It often appears before verbs (e.g., 尽早完成, 尽早联系) and carries a respectful, responsible tone. While not inherently urgent like 立刻 ('immediately'), 尽早 implies reasonable haste within practical constraints — for example, scheduling a medical check-up or submitting documents before a deadline.