how to say "serenity" in Hebrew...

שלוה

The Modern Hebrew letter ו (vahv) make a v sound when pronounced by most native speakers. In Biblical times, however, the letter made a w sound.

There are four Hebrew consonants pronounced, historically, at the lips: ב (b), מ (m), פ (p) and ו (w). Try it yourself. Linguists call these consonants bilabials. 

You all know the Hebrew word for peace - שָׁלוֹם (shah-LOHM). Here's the word for tranquility or serenity: שַׁלְוָה (shahl-VAH). 

Now let's look at the three-letter roots of these two words. The root of שלום is ש.ל.מ (sh.l.m.). The root of  שלוה is ש.ל.ו (sh.l.w). Two of the three letters in each of the two roots are identical: ש and ל. And the third letters - they're pretty close, as they're both pronounced at the lips. Such are many Hebrew synonyms. 

I write about this word because tonight I sat at the Western Wall with a couple of friends and sang in honor of one of them, who is getting married tomorrow. The first song we sang was יְהִי שָׁלוֹם בְּחֵילֵךְ, שַׁלְוָה בְּאַרְמְנוֹתָיִך (ye-HEE shah-LOHM be-kheh-LEKH, shahl-VAH be-ahr-meh-noh-TAH-yeekh) - May there be peace within your strongholds and tranquility within your palaces (Psalms 122).

May it be so.