Root م ط ر(m T r) has 6 unique word forms and appears 15 times in the Quran.

English gloss Rain, Pour out Shower

Word Translation Occurrences
وَأَمۡطَرۡنَا and We rained, And We showered 10
مَّطَرٗاۖ a rain 6
مَطَرُ (the) rain, (was) the rain 4
أُمۡطِرَتۡ was showered 2
مُّمۡطِرُنَاۚ bringing us rain 2
مَّطَرٍ rain 2
فَأَمۡطِرۡ then (send) rain 2
مَطَرَ (with) a rain 2