1. Sumukha (One who has a beautiful face)
Nobody has doubts in the divine beauty of Ganesha. And that beauty is connected with inner beauty and spiritual perfection.  He enunciates [bad word] nature of Omkara, which represents Lord Bramha, Lord Vishnu and Lord Shiva. 

2. Ekadanta (Having One Tooth)
Ganesha is the One Who is the embodiment (eka) of the supreme [bad word] (danta) and hence the name Ekadanta. The legend reporting that Ganesh broke His tusk when He fighted against the devil Gajamukhâsura has no other meaning : the demon is the ego of our daily life. When He breaks His tusk to conquer and destroy this demon, Ganesh, in the mean time, attains the Oneness state. His single tusk propagates Adwaitavad -  the doctrine of Onenness.

3. Kapila (The Lord of a tawny color)
Kapil is an adjective means of Grey colour. Kapila was also the name given to a celestial grey cow. Just as a cow contributes in keeping Man healthy through its milk, Ganesha too does the same for the human mind by passing on knowledge and wisdom. This nature of kind giving to Man is assimilated in the name, Kapila.

4.Gajakarna (One with ears of an elephant)
Long ears suggest that He is capable of listening everything. Therefore, the Ganesh ears shake the dust of vice and virtue, afterwards only the [bad word] virtue remains. Similarly, in the men's prayers, He is able to discriminate what is [bad word] and what is lie, which [bad word] from faith and which words are tarnished by impiety. In other words, Ganesha's ears indicate that such discrimination between Brahman and Maya is to be gained by taking recourse to Sravana (hearing). 

5. Lambodara (One with a large belly)
Lord Ganesha's large stomach contains all the known and unknown of the universe. It is the cosmic womb wherein may be found all that is. It represents a Highest Person having the entire Cosmos in himself, with a massive amount of spiritual energies and authority. "Without any doubt, a lot of boundless worlds are born from His belly"(Bhagavat Tattva)

6. Vikata (One who is ferocious or the Misshapen)
This name, which means ferocious or dreadful, is suggestive of Lord Ganesha taking on those forms to defeat all evils. Mudgala Purana describe Him, subdued Kama. 
Really, the battle against our inners enemies is the basis of the saddhana and this form demonstrate that Ganesh has the capacity to reduce all the human weaknesses.