I think you're thinking of Basque - that's the totally unrelated language to any other. Portuguese and Spanish are closely enough related that if you speak one, you can make yourself understood to someone who speaks the other. (My grandmother's second wife spoke Portuguese (from Mozambique) and English)

As for English - no, it's not Germanic, not like Low German, Dutch, and the others. I think it's a misnomer because of the assumptions that are made sometimes - and very poor imaginations by some linguists. The various Germanic languages are from the Indo-European chain of languages. What people think of as 'Germanic' languages the linguists call North Germanic, West Germanic, and East Germanic. Some of the articles I've seen must be very old, because they lump Dutch in with Frisian, where Frisian is actually related to English, Scots, and some extinct language groups from what is now Southern Germany. The Nordic countries are supposedly 'North Germanic' - even though they're not related to the area that was called the Germanies. (Germany didn't exist until the mid 1800's. Prior to that, it was a random loose confederation of princedoms with no real name, just referred to as 'The Germanies'. The Kaiser got tired of the constant mish-mash of tolls, taxes, and fees, and took it over into one country. So, if you hear of a German talking about how young the US is, you can point out that their country is younger.)

So, English, Frisian, and old Scots are still the same language group. Frisian picked up more of the Dutch words, and English picked up more Norman words - so they drifted apart. Old Scots picked up more Celtic words. The three languages are still much more closely related than, say, English to German. English is an Indo-European language, yes - but it's pretty clearly not Germanic like .. oh, say, German, Dutch, or Swedish. (We won't touch Finnish)