From Longman Dictionary of Contemporary EnglishPDAPDA /ˌpiː diː ˈeɪ/ noun 1 [countable] (personal digital assistant) a very small light computer that you can carry with you, and that you use to store information such as telephone numbers, addresses, and appointments. Some PDAs can send and receive email, and connect to the Internet.2 [countable, uncountable] (public display of affection) informal when someone kisses or touches their boyfriend, girlfriend, partner etc in public in a way that shows that they love them She and her new boyfriend engaged in a pretty obvious PDA at the celebrity party.
Examples from the Corpus
PDA• Smart phones combine today's mobile phone with a PDA to create a so-called smart device.• The second product, the A5 PaperTalk is essentially an up-market version of the Amstrad PDA.• Fellow passengers lean over to see what he's playing on the tiny screen of his handheld PDA.• Certainly your average Palm user doesn't make a habit of installing extra apps on his or her PDA, we reckon.From Longman Business DictionaryLBED_25_aPDAPDA noun [countable] COMPUTINGpersonal digital assistant; a very small light computer that you can carry with youSYNNOTEPAD, PALMTOP, PERSONAL ORGANIZER 