Motivation and semantic change

Sad (OE "satisfied with food" (сыт(ый) => "oversatisfied with food; having eaten too much". =>

• Sad (OE "satisfied with food" (сыт(ый) => "oversatisfied with food; having eaten too much". =>
• Sad developed a negative evaluative connotation “the physical unease and discomfort of a person who has had too much to eat”. =>
• Sad – “physical discomfort into one of spiritual discontent” =>
• Sad "melancholy", "sorrowful" developed, and the adjective describes now a purely emotional state. The two previous meanings ("satisfied with food" and "having eaten too much") were ousted from the semantic structure of the word long ago.