TgJ Is40:31 :וְיֵיספוּן חֵיל וְיִתחַדְתוּן לְעוֹלֵימוּתְהוֹן‏ : they shall add strength and be restored to their youthful state
See the entire entry for ḥdt vb. to be new

TgJ Is40:31 :וְיֵיספוּן חֵיל וְיִתחַדְתוּן לְעוֹלֵימוּתְהוֹן‏ : they shall regain strength and be renewed into their youthful state
See the entire entry for ˁŭlaymū, ˁŭlaymūṯā n.f. youthfulness

TgJ Is40:31 :וְיִתחַדְתוּן לְעוֹלֵימוּתְהוֹן כְצִימוּח דְסָלֵיק עַל גַדפֵי נִשרִין‏ : they shall be renewed to their youthful state like the growth that comes up on the wings of eagles
See the entire entry for ṣymwḥ v.n.D sprouting, growing