(Internet slang, text messaging) Alternative letter-case form of TTYL.

Initialism of ta ta for now; goodbye

(Internet slang, text messaging) Initialism of talk to you later.

Initialism of table-top proton synchrotron. / Initialism of telephone tax payment service.

(countable) Initialism of trusted third party. / (medicine, uncountable) Initialism of thrombotic thrombocytopenic purpura.

Initialism of Tehrik-i-Taliban Pakistan (“Pakistani Taliban”).

(chemistry) Initialism of triphenyl tetrazolium chloride. / Initialism of trying to conceive.

(Canada, transport) Initialism of Toronto Transit Commission.

Initialism of Trademark Trial and Appeal Board: an adjudicatory body of the United States Patent and Trademark Office.

teletypewriter (originally), or a text display device, as used by the deaf to read voice communication converted to text by a communication assistant device (CA).