Fall Looks. The word you'll hear in coming fashions is ''androgynous''

Word was around that hemlines would drop for fall, that shoes would have lower heels, that black would be less in evidence, and that mannish styles - known in current fashion parlance as ''the androgynous look'' - would be a dominant factor.

And sure enough, all these predictions (based partly on what buyers and press saw at recent advance showings in Europe) came true during the first week of autumn-winter openings here.

Oversize masculine clothes for women surfaced at many Seventh Avenue houses. Although some designers are making a point of avoiding the androgynous theme, nearly everyone has followed the trend to a discernible extent. The capacious topcoat with extra-roomy shoulders that reaches to well below calf appeared in myriad versions on many runways. The ratio between pants and skirts was almost evenly balanced, with the tailored, pleat-top trouser given a great deal of attention.

Hem lengths, a matter of contention last season, are descending measurably. Most designers agree on 31- to 33-inch skirts that cover the leg (a change that may prompt some women to forage through their closets for a salvageable maxi skirt).

In some cases - at Anne Klein & Co., for instance - only the ankle is visible. Sometimes not even that. Low suede boots with little curved heels often accompany the sweeping equestrian-style skirts featured by this firm.

''Boots are very important,'' says Donna Karan, who creates, with Louis Dell'Olio, the Anne Klein collection. ''Every length works with them. In boots, a woman will accept the idea of a long skirt.''

While adhering to its well-established sportswear formula, the Anne Klein line is freer this time. Besides the generously cut jackets of nubby tweed, there are cabled vests and elongated cardigans, cashmere dresses, and a choice between three-quarter and long coats. Skirts come in narrow and flared styles. Bypassing black completely, the designers concentrate on navy, shades of taupe, gray, white, and a soft russet red.

The components at Blassport are in a similar vein: a man's soft shirt, sweatervest, blazer, cuffed pants, or - for a different look - knee-length skirt , with a long swinging trench coat tossed over the combination. Everything is on the larger-than-life scale. Menswear fabrics like chalk-stripe flannels, coverts , glen plaids, and herringbones are given a slouchy air. The feminizing touches: shoulder-length hairdos and black patent ballet shoes.

The separates mixture at Adri centers on what this designer calls her ''slither skirt,'' a narrow, side-buttoned wrap that reveals the lower calf but not much else. Jumpers, fluffy mohair sweaters, leather waistcoats, and shirt jackets, as well as very long cardigans, are all in the picture. Her chocolate-with-beige and deep-navy-with-gray parts-dressing is relaxed and casual. It has no androgynous overtones. The music at the close of her show - ''I Did It My Way'' - was a reminder of her independent spirit.

Even more of a law unto herself, Mary McFadden ignores prevailing trends. She has dedicated her latest collection to the French Empire painter J.A.D. Ingres (an Ingres exhibition is now touring the country). But aside from turbans and neoclassical motifs used in beading and other embellishments, the clothes do not have much of an Ingres flavor. Evening dresses are as sumptuous as usual, including extraordinary panne velvet damasks and finely pleated gowns of rich, glowing red with antique gold braid trimmings. Timelessness rather than timeliness is the McFadden byword.

Another individualist, Harriet Winter (her label is Mrs. H. Winter), states firmly that she wishes women to look like women, ''not like adolescent boys or some indeterminate third sex.'' She understands perfect cut and proportion, as her all-enveloping kimono-sleeved coats bear witness. A new coat has a dropped waist and full, flaring skirt. Everything is long - at the below-calf length she has always liked. Columnar dresses that skim the body come in such rich materials as alpaca, chenille, cloque, and pure silk velvet - a choice fabric that most designers have forgotten.