Plural Hebrew words with a Singular Meaning

Here are some words that are plural in form, but can be singular (at times in meaning). This is obviously not an exhaustive list:

• Heaven (shah’mah’yim)
• Life (chaim)
• Water (mayim)
• Face (panim)
• Holy One (kedoshim)
• Teacher (morim)
• Maker (osim)
• Husband (baalim)
• Most High (elyonin, Aramaic).

The word Behemoth is the feminine plural of behemah, the common word for cattle or wild animals. 

The great multi-headed sea serpent Leviathan is also known as Tanninim or Tannim (plurals; Gen 1:21; Isa 51:9; Ezek 32:2; Ps 74:13; Job 7:12).

Physical things like "water" or "sky/heaven" or a human "face" are said to be plural in Hebrew because they have several dimensions to them, because they are not inherently static and always moving; their expressions are constantly shifting or altering; changing facets. There are different kinds of waters (mayim) and sky (shamayim).  And your face (panim) can convey numerous moods, intensities or frames of mind. Life (lives) is also a plural (chayim).

Some nouns which denote actions, when viewed as a series of activities, are also spoken of in plural terms. For example, the words "deliverance/salvation" (yeshuah), "parental love" (racham), or "steadfast love" (hesed) at times appear as yeshuot (feminine plural), rachamim, and hasadim. These are attributes of the boundless works of God that are done on behalf of his people.