Source: Tafsir al-Ahlam al-Kabir (Ibn Sirin)
Cucumber in a dream in its season is blessed sustenance. Out of season, it is illness and worry. Green cucumber indicates a righteous woman.
Source: Ta'tir al-Anam fi Ta'bir al-Manam (Al-Nabulsi)
Cucumber indicates worry and sadness. Eating it indicates falling into worry.
Source: Al-Isharat fi Ilm al-Ibarat (Ibn Shahin)
Cucumber is interpreted as worry. Whoever sees himself eat it will be afflicted with worry.