Originally, the character depicted a kneeling figure. The two horizontal lines (二) represents the figure’s head and the bottom part (儿) shows the kneeling. The original meaning of the character was ‘beginning’ or ‘head’, as something was heading to somewhere. Today the most common definition of this character is ‘dollar’.
Besides meaning ‘dollar’, the old meaning of 元: head (or beginning) still can be found in modern context. For example:
元月 = 元 (head) + 月 (month) = the head of the months = first month = January
元旦 = 元 (head; beginning) + 旦 (sunrise) = beginning of sunrise = the start of the year – New Year’s Day. Source: Chineasy