breath, respiration, son, interest (on money), rest, coming to an end
息 centers on the movement of air and the life it sustains: breathing and respiration. The meanings 'son', 'interest (on money)', and 'rest' are natural extensions—a son is one's own breath continuing, interest is the 'breath' or growth of money, and rest is a pause to catch one's breath. 'Coming to an end' can be seen as the final breath.
息 combines 自 (nose, self) and 心 (heart), suggesting breath coming from within. The original idea likely relates to breathing as a vital function tied to the heart or inner self.
The top 自 (self/nose) and bottom 心 (heart) together picture one's own heart breathing: 息 is the breath of life.
For ソク, imagine a sock puppet taking a deep breath: sock -> ソク, and the puppet's breath makes it come alive.
son
breath; breathing
inhabiting; living
sigh
rest; relief; relaxation
one breath
suffocation; choking; asphyxia
asthma
news (from someone); letter; contact
(another's) son
interest (on a loan, deposit etc.)
shortness of breath; panting; puffing
cessation; (coming to an) end
breath
nasal breathing; breathing through one's nose
breathing of a sleeping person
sigh (of grief, disappointment, etc.); grieving; lamenting; deploring
informed circles
lazy son; profligate son
only son
habitat; home (e.g. of the tiger)