the.com/dad

means An informal term for one's father, often connoting warmth and everyday familiarity rather than formality.

from One of the oldest layers of baby talk in human language — 'dad' or similar da/ta/papa sounds show up across unrelated language families because they're among the easiest syllables for infants to produce. English 'dad' is recorded from medieval times, likely passed down through nursery speech rather than borrowed from another language, which is why no one can trace it to a tidy single root.