A primitive root; properly, to become pale, i.e. (by implication) to pine after; also to fear -- (have) desire, be greedy, long, sore.
H3700. kasaph
[כָּסַף] verb long (for) (Arabic be colourless, obscure, be eclipsed (of sun or moon); also be depressed in appearance BaES 61; modern Arabic disappoint; reflexive conjugations be disappointed, ashamed, see SpiroVocab; Late Hebrew כסף Hiph`il shew pallor, be pale, white; Qal be ashamed, long for, compare Aramaic כְּסַף) —
Qal Imperfect2masculine singular תִּכְסֹ֑ףלְמַעֲשֵׂה יָדֶיךָ Job 14:15 for the work of thy hands thou wouldest long; 3 masculine singular לִטְרֹ֑ף יִכְסוֺף כְּאַרְיֵה Psalm 17:12 like a lion that longeth to rend.
Niph`al Perfect2masculine singular + Infinitive absolute אָבִיךָ לְבֵית נִכְסַפְתָּה נִכְסֹף Genesis 31:30 thou didst long sorely for thy father's house; Perfect3feminine singular י לְחַצְרוֺת נַפְשִׁי ֗֗֗ ׳נִכְסְפָה Psalm 84:4 my soul longeth . . . . for the courts of ׳י; Perfect3masculine singular נִכְסָ֑ף לֹא הַגּוֺי Zephaniah 2:1 very dubious; but perhaps (Ges Ew Hi Ke and others), O nation not turning pale, = not ashamed, compare etymology above; We thinks whole see corrupt.