Depends on context.

The **conductor of a symphony orchestra**, during rehearsal, would probably refer to that as **unison doubled at the octave.**

A **music theory student** would be chastised for calling it a chord. A chord must have three or more notes, by definition. However, it could be called an **implied chord** if the context justified it.

An **atonal composer** would refer to it as a **simultaneity composed of a several pitches but only one pitch class.**

A **musician in a rock band** trying to teach his group a song would probably not refer to it as a chord as that wouldn't really accurately tell them what to play. They would probably call it a **note**," e.g. a "A major chord, then E minor chord, then a C note." 

A **guitarist** might call it a **partial chord**.

A **computer programmer** writing, say, an Ableton plugin, might call it a special case of a **chord**, and it would be reasonable for a chord generator to allow for chords composer only of a single note at various octaves.