Strong's H5934עָלוּם: (only in plural as abstract) adolescence; figuratively, vigor KJV:youth.
Meanings: Brown-Driver-Briggs (1906) and Strong's Hebrew Dictionary (1890), public domain, via the Open Scriptures Hebrew Bible Project (CC BY 4.0). TWOT numbers for reference only.
Root family 1630: עלםʿlm — Root of: עָלוּמִים youth, youthful vigour; עֶ֫לֶם young man; עַלְמָה young woman