Grammar term · Sarf · morphology
مُفْرَد
mufrad

Singular

Sarf · morphologyNumber & plural typecore term25,253+ in the Qur'an
In one line
The singular: one of something — the base form from which dual and plural are built.
Classical definition
المُفْرَدُ مَا دَلَّ عَلَى وَاحِدٍ أَوْ وَاحِدَةٍ، كَرَجُلٍ وَامْرَأَةٍ.
“The singular is what indicates one (male or female), like rajul and imra'a.”
(بتصرف من شذا العرف)
Key words in the Arabic
وَاحِد أَوْ وَاحِدَةone — of either gender
Understand it

Mufrad here is the number term — one, as against the dual's two and the plural's three-plus. (Grammar reuses the same word elsewhere: a khabar can be 'mufrad' meaning not-a-sentence, and the munada can be 'mufrad' meaning not-in-idafa; keep the contexts apart.) Number-mufrad is the citation form: dictionaries list it, and the dual and plurals are manufactured from it.

How to spot it
Recognition test
One entity, no dual or plural ending, no broken-plural pattern: the noun as the dictionary gives it.
In the Qur'an
وَجَآءَ رَجُلٌ مِّنْ أَقْصَا ٱلْمَدِينَةِ يَسْعَىٰ
Al-Qasas 28:20 — “And a man came running from the farthest part of the city”
رَجُلٌ — one man: the bare mufrad, declining with ordinary tanwin.
Related terms
Domain: Sarf · Category: Number & plural type · Frequency in the Qur'an: 25,253 · Source: بتصرف من شذا العرف, cross-checked against the Quranic corpus · Reviewed by Ustad M. Arjan Ali