Definitions
In this Constitution, unless the context otherwise requires, the following expressions have the meanings hereby respectively assigned to them, that is to say—(1) 'agricultural income' means agricultural income as defined for the purposes of the enactments relating to Indian income-tax; ... (2) 'an Anglo-Indian' means a person whose father or any of whose other male progenitors in the male line is or was of European descent...; (10) 'existing law' means any law, Ordinance, order, bye-law, rule or regulation passed or made before the commencement of this Constitution...; (17) 'Scheduled Castes' means such castes, races or tribes or parts of or groups within such castes, races or tribes as are deemed under article 341 to be Scheduled Castes for the purposes of this Constitution; ... [and dozens more defined terms used throughout the Constitution's text].
What this Article actually means
How it shows up in everyday life
Whenever a legal dispute turns on the precise technical meaning of a constitutional term — like exactly what counts as a 'Money Bill' (relevant to legislative procedure) or the formal definition of 'Scheduled Castes' — this Article is very often where courts look first for the Constitution's own defined meaning.
Read alongside this one
Quick answers about Article 366
Why not just define each term where it first appears in the Constitution?
The text above reproduces Article 366 of the Constitution of India as amended to date, for general educational reference. It is public-domain legislative text, but we recommend cross-checking the authoritative version at legislative.gov.in or india.gov.in before relying on it for a legal matter. The explanation, examples and FAQs are general information, not legal advice — consult a qualified advocate for guidance on your specific situation.