A sugar daddy is the provider in a sugar dating relationship - typically older and wealthier than the recipient, who is known as a sugar baby. Dictionary.com defines the term as an older man who may give gifts, allowances and trips to a younger woman or man in exchange for a consensual relationship, and that definition is worth noting for two reasons: it treats the arrangement as consensual, and it does not restrict recipients to women.
The vocabulary is a century old. Dictionary.com records the term as first used between 1915 and 1920. The Oxford English Dictionary attributes its earliest evidence to a 1926 work by the British author Gilbert Frankau, My Unsentimental Journey, and Merriam-Webster together with The New Partridge Dictionary of Slang and Unconventional English date the term from at least 1926. Etymologists including Michael Quinion and Barry Popik note that print examples predate 1926, and point instead to the 1923 Dorothy "Dot" King case as the moment the phrase entered wide public use.
What has changed is not the vocabulary but the expectation of precision. On a structured platform, "sugar daddy" describes a role rather than a lifestyle label: the member who provides financial support, mentorship, travel access or lifestyle access, and who states that offer in a profile field instead of hinting at it across six weeks of conversation. The recipient states what she is looking for in the same structured way. Both then negotiate a mutually beneficial arrangement before meeting - frequency, discretion, travel and support are agreed in advance, not discovered later.