from Wiktionary, Creative Commons Attribution/Share-Alike License
- v. to open (a door, gate etc.)
from the GNU version of the Collaborative International Dictionary of English
- transitive v. To open.
from The Century Dictionary and Cyclopedia
- To open.
- n. A trough used in South Africa for sheep-washing.
Blend of do and up, from Middle English don up ("to open"). Compare don, doff, dout. (Wiktionary)