A cucumber - Taken literally this refers to the popular salad vegetable served by the English in sandwiches that have no taste whatsoever.
In Cyprus it performs a similar function - but is also used as something to growl contemptuously at times of disbelief.
This is based on the cucumber's topographical similarity to the male organ and thus gives rise to the phrase Afti theli angouri or "She wants (perhaps needs) a cucumber".
This implies that the female referred to requires a good seeing-to thus obliging her to desist with whatever she may be doing to upset the (usually) male employing the phrase.
If desired, you can pronounce the word angouri alone and with emphasis and vigour as an expression of disbelief and contempt or else frustration should you strike your thumb with a hammer for example. The newly-discovered similarity between your thumb and a small cucumber is here coincidental.
So, for example, when the man you thought was your lawyer (just because you were paying him) announces to you for the sixth time that the house his brother in law was supposedly building for you has had its completion date pushed back - and then advises you that there is nothing you can do about it this time either - growling angouri re malaga and lunging for his throat is entirely appropriate.
You should use Na when he tries to bill you for the consultation.
It is strongly recommended those persons wishing to acquire cucumbers take care to phrase their request cautiously to avoid embarrassment, consider asking for angourakia or small cucumbers which (in the anatomical sense) no true Hellene will ever admit to possessing.