What are the morphological patterns for adjectives in which the masculine and feminine, and the singular and plural, are equally applicable, and what are examples of them?

The feminine and masculine forms are equally applicable in adjectives of the patterns "mif'al," "mif'al," "mif'īl," and "fa'ūl" when they mean an active participle (fā'il). The same applies to "fa'īl" when it means a passive participle (maf'ūl), and to the patterns "fi'l" and "fa'al" when they mean a passive participle. This also applies to verbal nouns (masādir) when they are intended as descriptions. Similarly, the singular and plural, and masculine and feminine, are all equally applicable in "fa'īl" when it means a passive participle, and in "fa'īl" when it refers to a genus. This also applies to the words "kathīr" (many), "ẓahīr" (supporter), "al-ḥamīm" (close friend), "al-ṣadīq" (friend), "ʿaduw" (enemy), "junub" (one in a state of major ritual impurity), and "ḍayf" (guest).