unique, one of a kind, exceptional
Building blocks
- ainu - "one," "single," or "unique" 
- laadne - "-like" or "-ish" 
If you combine the meanings of these two words, “ainulaadne” literally translates to “one-like” or “single-ish”. Idiomatically it has come to mean “unique” or “one of a kind”
How to use it:
- Describing a unique object or item: - "Ta leidis antiigipoest ainulaadse kella." (He found a unique clock in an antique store.) 
 
- Talking about a one-of-a-kind experience: - “Meil oli täna ainulaadne võimalus kohtuda presidendiga.” (Today, we had the unique opportunity to meet the president.) 
 
- Describing a person's unique qualities or talents: - “Ta on ainulaadne muusik, kellel on oma unikaalne stiil.” (He is a unique musician with his own distinctive style.) 
 
- Discussing a unique place or location: - “See rannikuala on ainulaadne oma kauni looduse poolest.” (This coastal area is unique for its beautiful scenery.) 
 
Examples
Me kogesime täna midagi täiesti ainulaadset
Literally: “We experienced today something completely unique”
Idiomatically: “We experienced something completely unique today”
Me - Pronoun - Nominative Pl, "We"
kogesime - Verb - 1P Past Pl, "experienced"
täna - Adverb - Indeclineable, "today"
midagi - Pronoun - Partitive Sg, "something"
täiesti - Adverb - Indeclineable, "completely"
ainulaadset - Adjective - Partitive Sg, "unique"

