Syndr

As defined by A Concise Dictionary of Old Icelandic (Geir Zoëga):

syndr

a. able to swim; s. vel, a good swimmer; hann var s. sem selr, he could swim like a seal.

Possible runic inscription in Younger Futhark:ᛋᚢᚾᛏᚱ

Also available in related dictionaries:

This headword also appears in dictionaries of other languages closely related to Old Icelandic.

• Old Norse - Cleasby & Vigfusson Dictionary
• Old Norwegian - Johan Fritzner's Dictionary