Kulub

Kulub is the Arabic word that refers to the plural of qalb, meaning “hearts.” In standard Arabic, qalb denotes the heart and is used both literally and figuratively to denote the center of emotion, intention, or belief. Kulub (قلوب) is the masculine plural form of qalb and is commonly seen in religious, literary, and everyday contexts.

Transliteration and usage notes: The plural is most commonly transliterated as qulūb or quloob in English, but kulub also appears in some transliterations and older texts. The spelling varies with transliteration schemes, yet the underlying Arabic form remains قلـوب. Scholars distinguish between qalb (singular) and kulub (plural) as the grammatical unit, while the semantic usage remains connected to the heart as the seat of feeling, belief, and intention.

Semantic significance: In Arabic and Islamic literature, kulub and its related forms denote more than a physical organ. They describe inner states such as belief and doubt, sincerity and hypocrisy, compassion and hardness of heart. The term often appears in religious discourse to discuss spiritual conditions, moral character, or the openness of a person’s heart to faith, guidance, or revelation. In poetry and rhetoric, kulub can evoke emotional depth, inner conflict, or the contrast between outward behavior and inner conviction.

See also: qalb, quluub, qulub. These terms are related concepts in Arabic that center on the heart as the seat of emotion, thought, and spiritual life.