This paper focuses on different types of wordformation uniqueness. Wordformation uniqueness can be found in solitary wordformation structures, which the author defines as unique structures representing a specific wordformation type found in a single derivative. The basic and simplest type is represented by a unique affix in a single derivative in the respective language of a given time period. An example of this is the Czech noun obličej [‘face’]: the circumfix ob-ej (with -lič- as a radix to be found in the noun líce [‘cheek’]) is found in no other noun in the contemporary Czech. Another uniquely formed noun in contemporary Czech is the noun rukáv [‘sleeve’], derived from ruka [‘hand’] with the unique suffix -áv. Specific wordformation solitaires are theoretically conceived values. They are derivatives with a specific, but not uniquely found affix which is uniquely added to the stem of a single word of a specific part of speech, e.g. the very specific suffix -ule is added to the stem of the verb vrtět [‘to wag’] so that the noun vrtule [‘propeller’] is derived. This article shows that the notion of wordformation solitariness can be theoretically postulated on different levels of abstractness, both of the form and of the wordformation meaning.