Indicator

noun

/ˈɪndɪkeɪtər/

A substance — such as litmus, phenolphthalein, or methyl orange — that changes colour at a specific pH range to signal the endpoint of a chemical reaction or the acidity of a solution.

✍️ Usage in a UPSC answer

Per capita income alone is a misleading indicator of well-being, for it masks the stark inequalities that composite measures such as the Human Development Index are designed to expose.

Synonyms

signgaugemarkerbarometersignalbenchmark

Antonyms

distractionconcealmentred herring

🌱 Word Family

indicate (v), indication (n), indicative (adj), indicatively (adv), indicators (n pl)

🔡 Root

Late Latin indicātor = one who points out; Latin indicāre = to make known; in- = towards + dicāre = to proclaim

📜 Etymology

From Late Latin indicātor (one who points out), from Latin indicāre (to make known, point out), from in- (towards) + dicāre (to proclaim); first recorded in English in the 1660s.

🧠 Memory Hook

In-DICA-tor: think of the Latin dicare, 'to proclaim' — an indicator is a finger that 'proclaims' and points out (in-dicates) where things stand.

⚗️ General Science 📖 Seen in: Acids, Bases, Salts & Everyday Chemist...

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