From an unused root meaning to be lofty; a craggy rock, literally or figuratively (a fortress) -- (ragged) rock, stone(-ny), strong hold.
H5553. sela
I. סֶ֫לַע61 noun masculineJudges 6:20 crag, cliff, synonym צוּר; — absolute ׳ס 6:20 +, סָ֑לַע Numbers 20:10 +; construct סֶ֫לַע 1 Samuel 23:28; suffix סַלְעִי 2 Samuel 22:2 +, סַלְעוֺ Isaiah 31:9; plural סְלָעִים 2:21 +; —
1 literally cliff, crag Judges 6:20; Isaiah 2:21; 7:19; Amos 6:12; Numbers 20:8 (twice in verse); 20:10 (twice in verse); 20:11(compare Nehemiah 9:15; Psalm 78:16, and contrast the צוּר of Exodus 17:6), Numbers 24:21; Deuteronomy 32:13 (not elsewhere Hexateuch), + 10 t.; הַסּ ׳שֵׁן 1 Samuel 14:4 (twice in verse) tooth of the crag, i.e. sharp crag, so Job 39:28; excavated in cliff as place of burial Isaiah 22:16; abode of wild animals, ׳יַעֲלֵיסֿ 22:1, compare Psalm 104:18; Proverbs 30:26, of birds Job 39:28; Song of Solomon 2:14 (in figurative), compare Jeremiah 48:28, so of Edom Obadiah 3 = 49:16; compare (Numbers 24:21 above and) Isaiah 42:11; particular cliffs are: ׳ס עֵיטָם Judges 15:8, 11 compare 15:13, ׳ס (הָ)רִמּוֺן 20:45, 47 (twice in verse); 21:13 ׳ס הַמַּחְלְקוֺת 1 Samuel 23:28 compare 23:25; see also II.סֶלַע.
2 figurative, especially סַלְעִי of ׳י (only Psalms), Psalm 18:3 = 2 Samuel 22:2; Psalm 31:4; 42:10; 71:3; of Assyrian god Isaiah 31:9 (probably; compare צוּר Deuteronomy 32:31, 37); ס ׳צֵל כָּבֵד Isaiah 32:2 (simile of protecting care); figurative of security Psalm 40:3 (feet on cliff), מִשְׂגַּבּוֺ סְלָעִים מְצָדוֺת Isaiah 33:16; symbol of obstinacy מִסּ פְנֵיהֶם ׳חִזְּקוּ Jeremiah 5:3; ס ׳צְחִיחַ (bare cliff, literally glare of [the] cliff), in figure of openness, flagrancy Ezekiel 24:7-8, of razed city 26:4, 14 (only here Ezekiel); in figure of fall of Babylonian Jeremiah 51:25.