ひ弱 is read as ひよわ (hiyowa) and means weak.
ひよわ
hiyowa
びょうじゃく
weak (constitution)
ひんじゃく
poor
はくじゃく
feebleness
きょうじゃく
strength and weakness
なんじゃく
weakness
じゃく
-lower (seismic intensity)
せいしんはくじゃく
feeble-mindedness
きよわ
timid
いっきょうたじゃく
one strong, many weak
としよわ
child born in last half of the year
さいじゃく
weakest
ぶんじゃく
(enervating) attraction to books or learning