אנטי־

Ultimately from Ancient Greek ἀντί (antí, “against”).

אַנְטִי־‎ • (anti-)

1. Anti-: forming words and compounds indicating antagonism, hostility, complementarity, reversal, and so on.

   אנטישמי — antishémi — anti-Semitic

   אנטי־חומר — anti-khomer — antimatter

   אנטי גיבור — ánti gibór — antihero

   • 2011 October 19, Dalia Karpel (דליה קרפל),‎ “סיפורו המופלא של ההולנדי מהגליל, שעד יום מותו לא ידע שהוא יהודי‎”, (sipúr hamuflá shél haholándi meihagalíl, she'ád yóm motó ló yadá shehú y'hudí, “The amazing story of the Dutchman from the Galilee, who died never knowing that he was Jewish”), in Haaretz online:

     ‏כאתאיסטים ואנטי-מיליטריסטים, צמחונים ואנטי-אלכוהוליסטים, […]‎

     k'ate'ístim v'anti-militarístim, tsimkhoním v'anti-alkoholístim, […]
     As atheists and anti-militarists, vegetarians and anti-alcoholists, […]

• The prefix אנטי־‎ is sometimes written solid with the following word, sometimes joined to it by a makáf or hyphen, and sometimes separated from it by a space. This depends to some extent on the individual writer: for example, although the noun אנטי־חומר‎ (anti-khomer, “antimatter”) is most often written with a makáf (as here) or hyphen, it is also well attested with a space, and sporadically attested written solid.