'd

from The American Heritage® Dictionary of the English Language, 5th Edition.

• Contraction of had.
• Contraction of would.
• Contraction of did.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb had (marking the pluperfect tense)
• verb Had, possessed.
• verb would
• verb colloquial Did.
• suffix archaic traditional English past tense indicator, largely replaced by -ed.
• suffix Used to form the past tense of some verbs that are in the form of numerals, letters, and abbreviations, especially in online communication. Compare ’s.