Star Trek: Deep Space Nine1993

[Odo tells Kira about the origin of his name]

Odo:
As you know, when Doctor Mora first brought me to his laboratory, it was under Cardassian supervision. All specimens had to be clearly labeled in Cardassian, so the overseers would always know what the scientists were working on. Since no one was exactly sure what I was, Mora labeled me 'Unknown Sample', which the overseer translated into Cardassian as 'Odo'ital'.

Major Kira:
So your name is 'Unknown Sample'?

Odo:
No. No. 'Odo'ital' literally means the word 'nothing'. Even after it became clear that I was sentient, the Bajoran scientists kept calling me that. As a joke, they split it into two words, like a Bajoran name: Odo Ital. Which eventually got shortened...

Major Kira:
...to Odo.

Odo:
But, now, the thing is, for the longest time, whenever anyone would use my name, the first thing I would think of was what it meant, 'nothing'. What better way to describe me? I had no family, no friends, no place where I belonged. I thought it was the most appropriate name anyone could give me. And then I met you.

[pause]

Odo:
...And the others - Sisko, Dax, even Quark. And now, when I hear one of you call me Odo, I no longer think of myself as nothing. I think of myself as me.