Adam Levine has a tattoo on his chest that says Tapas in Sanskrit, but he also has two vertical lines after the usual writing for Tapas that I see. I've seen these lines in Sanskrit writing, I just don't know what they mean, and I don't know why they would be in Adam's tattoo, so if someone could explain to me the difference between Tapas with the two lines after it and Tapas without them, it would be greatly appreciated.

The two lines are essentially meaningless. The pair of lines is a punctuation mark used in Sanskrit, called the double danda (sort-of explained on Wikipedia). This punctuation mark is used to indicate the end of a verse, and sometimes the beginning and end of an invocation, etc. In the case of the tattoo, it (like the tattoo itself :p) serves nothing more than a decorative purpose.

I like the tattoo :)

तपस is tapas, a Sanskrit word for Sun.

Two Lines are end the lines or can say full stop. And rest the word exact meaning , go to wiki link.

http://en.wikipedia.org/wiki/Tapas_(Sanskrit)

A word for the sun.
Also can be loosely translated as - Fire or "On Fire".

Passionate.

Also sort of Tapasy� - meaning "to pray" with suffering.

The last two lines are called "Purna Viram" meaning "to stop". Which is a Hindi version of Full stop.

Yeah, these guys are correct - although I should add that in Sanskrit literature (which is most often encountered as Hindu and Buddhist religious text presented poetically), a single vertical line often appears at the end of the first sentence of each couplet. This makes it function like a semicolon in English (;). The double-danda (double line as in his tattoo) would end the couplet in the poem, functioning as a fullstop/period as mentioned above.

Because he only has one word (tapas), the fullstop is unnecessary and in terms of Sanskrit syntax, entirely meaningless/incorrect.

In any event, it's a pretty cool tattoo nevertheless and he looks awesome just the same B)

Ta Pa S = Tapas also called Tapasya means effort. Usually the word refers to the effort made by saints to attain salvation. Meditation in the name of god is Tapasya. A human soul burning with the desire to salvation that is to say.
The word seems to be written in Hindi because Hindi which is the most recent of the Indian languages incidentatlly happens to share its script with Sanscrit which is considered the mother of all Indian languages. Hence a 'saint' is called a 'Tapasvi'.
The two vertical bars at the end are just punctuation. They indicate 'period' but is used in sanscrit at the end of couplets and sentences.

"desire" "or craving"

Correction, it means essentially the opposite, "penance".

Tapas has got nothing to do with desire or craving or penance.
Tapas means effort. Effort is incontrovertibly THE correct meaning of Tapas.

Desire means Kaam. It's from this word is the word Kaamasutra is derived.
Kaam in a generic sense means any desire.like Moksha+kaami = the one who desires salvation.
Penance is PrayasChitta.
In anycase Tapas means effort.
Tapasvi is the one who makes an effort. The word usually is used to refer to making an effort towards sefl-realization and salvation.
But literally making any serious effort is Tapas.
Tap on the other hand also means burning. Nevertheless the suffix 's' changes the meaning to effort.

‘Tapasya’ means ‘inner heat/fire’. uaually associated with spiritual purification &Yoga.

Tapas, (Sanskrit: “heat,” or “ardour”), in Hinduism, ascetic practice voluntarily carried out to achieve spiritual power or purification. In the Vedas, tapas refers to the “inner heat” created by the practice of physical austerities and figured in the creation myths, as a means by which Prajāpati (the main creator god) brought the world into existence. In later Hinduism the practice of tapas was especially associated with yogic discipline as a way of purifying the body in preparation for the more exacting spiritual exercises leading to liberation (moksha).

Being An Indian... I can answer your question. 'Tapas' or 'Tapasya' Literally Means 'Hard Work To Impress God' in Sanskrit & Pali Languages. And Those 2 Vertical Lines Refer to 'Purna Viram' or we can say Ending Of A Paragraph in Indian Languages Like Punjabi, Hindi, Sanskrit, Urdu, Bengali, etc... Just Like we Have Full Stop In English or any other European Language. In Purna Viram, Purna Means Fully And Viram Means Rest or End..