From Persian دل (dil), meaning "heart," which itself derives from Old Iranian *dil. Persian loanwords entered Hindi and Urdu extensively during the Mughal period (16th–18th centuries), and دل / दिल became one of the most deeply embedded of all, appearing in hundreds of compound words and idiomatic phrases.

In Hindi and Urdu poetry (shayari), दिल is arguably the single most important word — it is the canvas on which love, longing, and loss are painted. Phrases like दिल टूटना (dil ṭūṭnā, "heartbreak"), दिल लगाना (dil lagānā, "to fall in love / to apply oneself"), and दिल की बात (dil kī bāt, "what's in one's heart") are woven into everyday speech. Bollywood song titles and lyrics lean on दिल so heavily that it has become almost a cultural shorthand for the entire romantic genre. Non-native speakers should note that दिल almost always refers to emotional states; for the literal anatomical heart in a medical context, हृदय (hṛdaya) or दिल दौरा (heart attack) is used.