big = كَبِيْر
كَبِيْر (kabir) can mean old or great or big. The associated verbs with these meanings are كَبِرَ (kabira) (imperfect: يَكْبَر , verbal noun كِبَرًا ) to become older, and كَبُرَ (kabura) (imperfect: يَكْبُر , verbal nouns كِبَرًا and كُبْرًا ) to be great or to be big. The latter verb can refer to the size of something, or its importance or momentousness, e.g. كَبُرَ الرَّجُلُ كَثِيْرًا the man became very large, and كَبُرَ الأَمْر the affair became momentous. Note that كَبِرَ الرَّجُلَ كَثِيْرًا would mean the man became very old (i.e. aged a lot).