AMBER. A hard resinous substance of vegetable origin, generally of a bright yellow colour, and translucent. It is chiefly obtained from the southern shores of the Baltic, and those of Sicily, where it is thrown up by the sea, but it also occurs in beds of lignite. AMBERGRIS. A fragrant drug found floating on sea-coasts, the origin and production of which was long a matter of dispute, although now known to be a morbid product developed in the intestines of the spermaceti whale (_Physeter macrocephalus_). It is of a grayish colour, very light, easily fusible, and is used both as a perfume and a cordial, in various extracts, essences, and tinctures. AMBIENT [from _ambio_, Lat., to go round]. Surrounding, or investing; whence the atmosphere is designated ambient, because it encompasses the earth. AMBIGENAL. One of the triple hyperboles of the second order. AMBIT of a geometrical figure is the perimeter, or the line, or sum or all the lines, by which it is bounded. AMBITION is usually denominated a virtue or a vice according to its direction; but assuredly more of the former, as it is a grand stimulus to officers to avoid reproach, and aspire to eminence and honour. AMBLYGON. Obtuse angular. AMBRY. _See_ AUMBREY. AMBUSCADE [Span. _emboscada_]. A body of men lying in wait to surprise an enemy, or cut off his supplies; also the site where they lurk. This, as well as _ambush_, obviously arose from woods having afforded hiding-places. AMBUSH. Signifies an attempt to lie in concealment for the purpose of surprising the enemy without his perceiving the intention until he is attacked. AMELIORATION. An allowance made to the neutral purchaser, on reclaiming a ship irregularly condemned, for repairs she has undergone in his service. AMICABLE NUMBERS are such as are mutually equal to the sum of each other's aliquot parts. AMIDSHIPS. The middle of the ship, whether in regard to her length between stem and stern, or in breadth between the two sides. To put the helm _amidships_ is to place it in a line with the keel. The term, however, has a more general bearing to the axis of the ship; as guns, or stores, or place amidships has reference to that line, fore and aft. Externally the term "amidships" as to striking, boarding, &c., would be about the main-mast, or half the length of the ship. (_See_ MIDSHIPS.) AMIDWARD. Towards the 'midship or middle section of the vessel. AMLAGH. A Manx or Gaelic term denoting to manure with sea-weed. AMLEE. A Manx or Gaelic term for sea-weed.