fountain pen

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

• noun A pen having a refillable or replaceable ink reservoir that feeds ink to the nib.

from The Century Dictionary.

• noun A writing-pen with a reservoir for furnishing a continuous supply of ink.

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

• noun A pen containing a reservoir of ink, which is fed to a writing nib automatically.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a pen that is supplied with ink from a reservoir in its barrel