To an extremely negative degree that can hardly be put into words; extraordinarily bad or great.
example
Die Zustände in dem Lager waren von unsäglicher Grausamkeit geprägt.
The conditions in the camp were marked by unspeakable cruelty.
Usage tips
Word structure
The word consists of the prefix 'un-' and 'säglich,' which is derived from the verb 'sagen' (to say). 'Unsäglich' (unspeakable) therefore literally means that something is so extreme that one can hardly put it into words or speak of it.
EXAMPLE
Der Film war von einer unsäglichen Langeweile.
The film was filled with unspeakable boredom.
Typical collocations
'Unsäglich' (unspeakable) is used almost exclusively with negative, abstract nouns to emphasize their extreme extent. Common combinations are 'unsägliches Leid' (unspeakable suffering), 'unsäglicher Schmerz' (unspeakable pain), or 'unsägliche Dummheit' (unspeakable stupidity).
EXAMPLE
Er hat mit seiner Bemerkung unsägliches Leid verursacht.
He caused unspeakable suffering with his remark.
Register
This adjective belongs to elevated written language and is rarely used in everyday conversation. It gives a statement great weight and a formal, serious tone.
EXAMPLE
Die Zerstörung durch den Krieg war unsäglich.
The destruction caused by the war was unspeakable.
Compare with
near_synonym
unsäglich vs schrecklich
terrible
'schrecklich' and 'unsäglich' can both express something very negative or very intense. 'schrecklich' is widely usable in everyday language and can refer to an unpleasant experience, poor quality, or strong emphasis. 'unsäglich' sounds stronger and somewhat more elevated. It says that the extent is so bad or so great that it can hardly be described. 'unsäglich' is often used with suffering, pain, effort, or especially bad conditions. 'schrecklich' fits many normal situations, while 'unsäglich' emphasizes an extreme degree.
unsäglich
Nach der Absage war seine Enttäuschung unsäglich groß.
After the rejection, his disappointment was unspeakably great.
schrecklich
Im Zug war es wegen der Hitze schrecklich eng.
Because of the heat, it was terribly cramped on the train.